High left ventricular mass index does not limit the utility of fractional flow reserve for the physiologic assessment of lesion severity.

OBJECTIVES: To demonstrate that fractional flow reserve (FFR) of vessels in patients with high left ventricular mass index (LVMI) should be similar to that of matched vessels in patients with normal LVMI. BACKGROUND: FFR is a physiologic index of coronary lesion severity. It is not known whether FFR remains useful in the setting of increased LVMI, when microvascular abnormalities may be present. METHODS: LVMI was calculated in 84 patients using contrast left ventriculography after validation with cardiac magnetic resonance imaging. Cardiac risk factors, LV ejection fraction (LVEF), minimal lumen diameter (MLD), percent diameter stenosis (%DS), lesion length and FFR were compared in 22 patients with high LVMI to 62 patients with normal LVMI and angiographically-matched vessels. RESULTS: LVMI was 126 +/- 21 g/m2 in the high LVMI group and 84 +/- 21 g/m2 in the normal LVMI group. There were no differences in age, LVEF, diabetes, hypertension or dyslipidemia between groups. Angiographic lesion characteristics were well matched in patients with high versus normal LVMI (MLD 1.3 +/- 0.6 mm vs. 1.3 +/- 0.6 mm, %DS 61 +/- 13% vs. 62 +/- 13%, and lesion length 14.2 +/- 7.0 mm vs. 14.3 +/- 7.0 mm; p = NS for all). Importantly, no difference in FFR was observed (0.79 +/- 0.12 vs. 0.78 +/- 0.16; p = NS) between the groups, and LVMI did not correlate with FFR in a multivariate analysis. CONCLUSIONS: FFR of coronary lesions in patients with high LVMI is no different than FFR of angiographically-matched lesions in patients with normal LVMI, suggesting that high LV mass should not limit the utility of FFR as an index of coronary lesion severity.

Outcome of patients with acute coronary syndromes and moderate coronary lesions undergoing deferral of revascularization based on fractional flow reserve assessment.

OBJECTIVES: To determine the outcome of consecutive patients with and without acute coronary syndromes (ACS) in whom revascularization was deferred on the basis of fractional flow reserve (FFR). BACKGROUND: FFR < 0.75 correlates with ischemia on noninvasive tests and deferral of treatment on the basis of FFR is associated with low event rates in selected populations. Whether these low event rates apply to patients undergoing assessment of moderate stenoses in association with an ACS is not known and is an important clinical question. METHODS: Retrospective analysis and 12 month follow-up of consecutive, moderate (50-70%) de novo coronary lesions assessed with FFR. RESULTS: Revascularization was deferred in 120 lesions (111 patients) with FFR > or = 0.75. ACS was present in 35 patients (40 lesions). The clinical, angiographic and coronary hemodynamic characteristics of patients with and without ACS were similar. Among the 35 patients with ACS, there were 3 deaths, 1 MI, and 6 target vessel revascularizations (TVRs) (15% of lesions). Among the 76 patients without ACS, there were 5 deaths, 1 MI, and 7 TVR's (9% of lesions). CONCLUSIONS: Deferral of revascularization based on FFR in patients with ACS and moderate coronary stenoses is associated with acceptable and low event rates at 1 year.

Neointimal formation in two apolipoprotein E-deficient mouse strains with different atherosclerosis susceptibility.

C57BL/6 (B6) and C3H/HeJ (C3H) are two commonly used mouse strains that differ markedly in atherosclerosis susceptibility. In this study, we determined plaque formation after removal of the endothelium in the two strains carrying the mutant apolipoprotein E gene (apoE(-/-)). At 10 weeks of age, male B6.apoE(-/-) and C3H.apoE(-/-) mice underwent endothelial denudation of the left common carotid artery. Two weeks after injury, B6.apoE(-/-) mice developed significantly larger neointimal lesions in the vessel than their C3H.apoE(-/-) counterparts, although they had comparable plasma cholesterol levels on a chow diet. Feeding of a Western diet aggravated lesion formation in both strains, but the increase was more dramatic in B6.apoE(-/-) mice than in C3H.apoE(-/-) mice. Immunohistochemical and histological analyses demonstrated the presence of macrophage foam cells in neointimal lesions. We then compared neointimal growth in F1 mice reconstituted with bone marrow from B6.apoE(-/-) and C3H.apoE(-/-) mice. No significant lesions were observed 2 weeks after endothelial denudation in the mice reconstituted with bone marrow from either donor. Thus, these data indicate that foam cell formation contributes to neointimal growth in the hyperlipidemic apoE(-/-) model and that neither endothelial cells nor blood cells alone explain the dramatic difference between B6 and C3H mice in plaque formation.

Comparison between visual assessment and quantitative angiography versus fractional flow reserve for native coronary narrowings of moderate severity.

We tested the hypothesis that experienced interventional cardiologists can identify patients with fractional flow reserve (FFR) <0.75 either by visual assessment of the angiogram or by quantitative coronary angiography (QCA). Estimation of the significance of moderate lesions is difficult. FFR can determine the physiologic significance of a stenosis. Data comparing visual assessment and QCA of moderate lesions with FFR are limited. FFR was measured in 83 moderate lesions defined as having a 40% to 70% stenosis by visual inspection. An FFR <0.75 was considered "significant." Lesions were visually assessed by 3 experienced interventional cardiologists and their significance estimated. QCA was performed. Both analyses were compared with FFR. FFR averaged 0.82 +/- 0.11 and was <0.75 in 15 of 83 lesions (18%). The reviewers' classification was concordant with the FFR in about half the lesions. Concordance between reviewers was poor (Spearman's rho = 0.36). Visual assessment resulted in good sensitivity (80%) and negative predictive value (91%), but poor specificity (47%) and positive predictive value (25%) compared with FFR. By QCA, no patient with stenosis <60% or minimal luminal diameter >1.4 mm had FFR <0.75. QCA did not discriminate the significance of lesions outside of these parameters. Thus, neither visual assessment of an angiogram by experienced interventional cardiologists nor QCA can accurately predict the significance of most moderate narrowings.